Update changelog based on model updates

Author: aws-sdk-python-automation

.changes/next-release/api-change-paymentcryptography-77820.json

@@ -0,0 +1,5 @@
+{
+  "type": "api-change",
+  "category": "``payment-cryptography``",
+  "description": "Add support for certificates to be signed by 3rd party certificate authorities.  New API GetCertificateSigningRequest API and support for providing certificates at run-time for tr-34 import/export"
+}